Radio-frequency electromagnetic oscillations may be excited in RF resonators. RF resonators may also be designated as cavity resonators. RF resonators are used, for example, in particle accelerators for accelerating electrically charged particles.
In order to excite a radio-frequency electromagnetic oscillation in an RF resonator, it is known to generate a radio-frequency power by a klystron or a tetrode, for example, to transport the power by a cable or a waveguide to the RF resonator and to couple the power into the RF resonator there via a radiation window or an RF antenna. However, very high RF powers cannot be obtained with this type of excitation.
EP 0 606 870 A1 discloses equipping an RF resonator with a conductive wall and with a plurality of solid-state transistors, which are provided for inducing a radio-frequency electric current flow in the wall of the RF resonator and thereby exciting a radio-frequency electromagnetic oscillation in the RF resonator. In this case, the excitation of the current flow takes place by the application of a radio-frequency electrical voltage via an electrically insulating circumferential slot in the wall of the RF resonator.
A use of RF resonators in particle accelerators for accelerating electrically charged particles requires evacuation of the RF resonator to a very low pressure. It has been found that electrically insulating slots filled with dielectric material in otherwise conductive walls of an RF resonator may be sealed only with difficulty and in a complex manner. In particular, different thermal expansions of the conductive and insulating materials may lead to leakages arising.